Impact of exposure to phenols during early pregnancy on birth weight in two Canadian cohort studies subject to measurement errors

BACKGROUND

It is of interest to know whether early pregnancy exposure to phenols such as bisphenol-A (BPA) or triclosan (TCS) negatively impacts birth weight outcomes. Exposure to these chemicals is widespread in the Canadian population but obtaining accurate measurements of average exposure is difficult because these chemicals are rapidly excreted from the body, causing body levels to fluctuate both within and between days, as observed in a recent Canadian study (P4). This measurement error can attenuate the estimated effects of exposures.

METHODS

Data from two Canadian cohort studies, the Plastics and Personal-care Products use in Pregnancy (P4) Study and the Maternal-Infant Research on Environmental Chemicals (MIREC) Study, such that all participants with complete BPA or TCS exposure and outcome data were used (MIREC n = 1822, P4 n = 68). We used regression calibration to correct for the attenuating effects of exposure measurement error when modeling the effect of first trimester BPA or TCS exposure on four birth weight outcomes: birth weight (BW), low birth weight (LBW), small for gestational age (SGA) and large for gestational age (LGA). Specific gravity, time of day, and time since last urine void were also controlled in the analysis.

RESULTS

TCS exposure has a marginally significant association with SGA only with odds ratio 0.87 and 95% confidence interval (0.74, 1.00). It also has a marginally significant association with LGA in male offspring with odds ratio 1.11 and 95% confidence interval (1.00, 1.25). The effects of BPA on the four birth outcomes were insignificant.

CONCLUSIONS

Increased TCS exposure during pregnancy is marginally associated with decreased odds of having SGA offspring. It is possibly associated with decreased BW in males and decreased odds of LBW, though these associations were not present in measurement error corrected models. TCS is possibly associated with increased odds in male offspring of being LGA, though this relationship was not present in models not corrected for measurement error. The study finds no significant effects of BPA on birth weight outcomes, which may be due to more severe measurement error in a single observation of BPA.

Use of the non-pneumatic anti-shock garment (NASG) to reduce blood loss and time to recovery from shock for women with obstetric haemorrhage in Egypt

Obstetric haemorrhage is one of the leading causes of maternal mortality. In many low-resource settings, delays in transport to referral facilities and in obtaining lifesaving treatment, contribute to maternal deaths. The non-pneumatic anti-shock garment (NASG) is a low-technology pressure device that decreases blood loss, restores vital signs, and has the potential to improve adverse outcomes by helping women survive delays in receiving adequate emergency obstetric care. With brief training, even individuals without medical backgrounds can apply this first-aid device. In this secondary analysis of hospital data from a pre-post intervention study in Egypt (N=364 women with obstetric haemorrhage and shock), 158 received standard care, while 206 received standard care plus the NASG. The NASG significantly reduced blood loss, time to recovery from shock, and, for those with postpartum haemorrhage due to uterine atony who received oxytocin, the NASG had a significant effect on blood loss independent of oxytocin. These results indicate that the NASG may be a valuable innovation for reducing maternal mortality in low-resource settings. Testing at community and household levels will be necessary in order to determine whether the NASG can help women survive the longest delays.

First aid for obstetric haemorrhage: the pilot study of the non-pneumatic anti-shock garment in Egypt

OBJECTIVE

To compare the effect of non-pneumatic anti-shock garment (NASG) on blood loss from obstetric haemorrhage with standard management of obstetric haemorrhage.

DESIGN

Observational study of consecutive obstetric haemorrhage cases before and after introduction of the NASG.

SETTING

Four tertiary care maternity facilities in Egypt.

SAMPLE

The sample consisted of women with obstetric haemorrhage and signs of shock and the entry criteria were: >750 mL of blood loss and either pulse of >100 beats per minute or systolic blood pressure of <100 mmHg. A total of 158 women were in the preintervention group and 206 in the postintervention group.

METHODS

All the women with haemorrhage meeting the eligibility criteria were treated according to the standard protocol for 4 months (May-August 2004); blood loss was measured and recorded. The NASG was then introduced, and all the women meeting the eligibility criteria were treated according to the standard haemorrhage protocol plus the NASG for 4 months (September-December 2004).

MAIN OUTCOME MEASURES

Measured blood loss collected in a closed-end, graduated, plastic, under buttocks collection drape.

RESULTS

Median measured blood loss in the drape following study entry was 50% lower in those treated with the NASG (250 versus 500 mL, P < 0.001). There was also a non-statistically significant decrease in morbidity and mortality.

CONCLUSIONS

This is the first comparative study of the NASG with a standard obstetric haemorrhage treatment protocol. The NASG shows promise for management of obstetric haemorrhage, particularly in lower resource settings. Larger studies will be needed to determine if the NASG contributes to statistically significant decreases in morbidity and mortality.